Microtubules as a Critical Target for Arsenic Toxicity in Lung Cells in Vitro and in Vivo

To understand mechanisms for arsenic toxicity in the lung, we examined effects of sodium m-arsenite (As3+) on microtubule (MT) assembly in vitro (0–40 µM), in cultured rat lung fibroblasts (RFL6, 0–20 µM for 24 h) and in the rat animal model (intratracheal instillation of 2.02 mg As/kg body weight, once a week for 5 weeks). As3+ induced a dose-dependent disassembly of cellular MTs and enhancement of the free tubulin pool, initiating an autoregulation of tubulin synthesis manifest as inhibition of steady-state mRNA levels of βI-tubulin in dosed lung cells and tissues. Spindle MT injuries by As3+ were concomitant with chromosomal disorientations. As3+ reduced the binding to tubulin of [3H]N-ethylmaleimide (NEM), an -SH group reagent, resulting in inhibition of MT polymerization in vitro with bovine brain tubulins which was abolished by addition of dithiothreitol (DTT) suggesting As3+ action upon tubulin through -SH groups. In response to As3+, cells elevated cellular thiols such as metallothionein. Taxol, a tubulin polymerization agent, antagonized both As3+ and NEM induced MT depolymerization. MT–associated proteins (MAPs) essential for the MT stability were markedly suppressed in As3+-treated cells. Thus, tubulin sulfhydryls and MAPs are major molecular targets for As3+ damage to the lung triggering MT disassembly cascades

Alliances of networks & networks of alliances; international cooperation in mobile telecommunications

This paper introduces a social network perspective to the study of telecommunication alliances, with a focus on the international roaming agreements as our unit of analysis. Main issues include the influence of various firm and country-specific factors on the formation of inter-carrier relationships and how formalized alliances affect these inter-carrier relationships

SafePay: Protecting against Credit Card Forgery with Existing Magnetic Card Readers

Existing magnetic cards adopt plain text to store confidential information, thus being vulnerable to an untrusted credit card reader or a skimming device. To tackle the problem, researchers have proposed several new techniques such as integrated circuit card (IC card) and mobile wallet applications; however, none of them can support existing magnetic card readers thereby facing backwards compatibility issue.\ud \ud In this paper, to combat such credit card information leakages and remain backwards compatible, we propose SafePay, a system that transforms disposable credit card information to electrical current and drives a magnetic card chip to simulate the behavior of a physical magnetic card.\ud \ud We have implemented a prototype system of SafePay by a mobile phone and a prototype magnetic card chip. In the evaluation, we show that the current cost is about $0.5 excluding the phone, and the cost can be even lowered if manufactured in large scale. We also evaluated the prototype in experimental environment such as oscilloscope and real-world scenarios such as vending machines. The results show that the physical signal in oscilloscope is the same as the theoretical value, and meanwhile, we can successfully buy products in all the tested real-world scenarios

Internal mammary artery injury during percutaneous coronary intervention: a case report

Abstract Background Percutaneous coronary intervention (PCI) is widely used to treat coronary artery disease (CAD). However, complications of PCI are inevitable. Internal mammary artery (IMA) injury is an infrequent but potentially lethal complication of PCI. Case presentation A 78-year-old man was diagnosed with multivessel lesions by coronary angiography. The IMA was injured during PCI, then cured by early identification and active rescue. Conclusions This is the first reported case, to our knowledge, of injury to the IMA during PCI. We we report this case to discuss how to treat this injury effectively and avoid this complication during clinical therapy